The automatic dishwasher is widely used in homes and restaurants to clean and sanitize articles, for example tableware, dishes, flatware, pots, pans, etc. A dishwasher contains movable racks disposed in a cavity accessed via a watertight latchable door. A typical automatic dishwasher has two racks, each of which can move in and out of the cavity to facilitate unloading clean dishes from the racks and in loading soiled dishes in the racks. In use, the user opens the door, places the articles on the racks, adds detergent, latches the door, and initiates a cleaning cycle. The washer washes the articles with soapy water or other cleansing liquid, rinses the articles, optionally dries the articles and then holds them in the racks until removed. With the time pressures of modern society, the user of the automatic washer does not stand by for the dishwasher to complete it's cycle of washing and drying. Rather, the user attends to other matters while the articles are being washed. Indeed, it may be many hours (or even days) before the user returns to the dishwasher and opens the door. At that time the user may have forgotten that the articles inside are clean. Thus, the user (or another person) may mistakenly add newly soiled dishes to those that are clean and will realize, too late, that the dishes in the washer were clean. Now, the entire load of articles should be washed again to ensure that they are all clean. This results in aggravation, lost time and additional expense in hot water and soap. For the foregoing reasons there is a need for an easy-to-use signalling device to convey the wash status of articles disposed within a dishwasher.